Contents of pressure vessel records and safety management

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Archive content: Technical archives for pressure vessels should be established. In order to have a comprehensive understanding of the condition of these devices, to understand their patterns of use, and to prevent accidents resulting from improper use, it is necessary to maintain complete technical archives for each pressure vessel. The archives should include the original technical data and usage records of the container, as well as inspection and repair records. 1. Original technical documents of pressure vessels: The original technical documents of a vessel include its design documents and manufacturing documents. The design documents for the container should include a general layout diagram of the container and diagrams of its pressure-bearing components. Pressurized components of medium-high pressure or low-temperature vessels shall have a strength calculation report. Containers designed based on stress analysis should also include data on local stress calculations, etc. The manufacturing documents for the container should include a factory certificate of conformity, a technical specifications sheet, and a quality certificate. The quality certificate should include the chemical composition and mechanical properties of the main components, the results of non-destructive testing, the results of welding quality inspections, as well as the results of pressure tests and airtightness tests. The above information is provided by the design, manufacturing, and installation units; at the time of completion inspection, the installation unit hands it over to the user unit along with the container. 2. Records of use and maintenance of pressure vessels: operating pressure and temperature of the vessel, working medium, range of fluctuations in pressure and temperature, intermittent operation cycle, properties of the working medium, etc. The date when the container was first put into use, the dates of each start and stop, and any changes to the usage conditions, etc. The date of each inspection of the container, the contents of the inspection, the inspection results, the results of pressure testing, any defects found, and the repairs carried out, etc. The usage records of pressure vessels shall be filled out on time and properly kept by equipment managers or operators. When a pressure vessel is transferred away from its original user, the technical documentation must be handed over to the new user along with the vessel itself. Safety operating procedures: Improper operation is a common cause of accidents involving pressure vessels. To ensure the safe and proper use of containers, it is necessary to establish safety operating procedures for pressure vessels based on the requirements of the production process and the technical characteristics of the vessels. These procedures should include the following points: 1. The maximum allowable pressure and allowable limit temperature of the vessel ； 2. Correct operating methods for containers ； 3. Operating procedures and safety precautions for starting up and shutting down ； 4. Inspection items, locations, and normal requirements during container operation ； 5. Possible abnormal phenomena in containers, methods for identification, and emergency measures ； 6. Inspection and maintenance after the container is taken out of service. Every operator must strictly adhere to the safety and technical operating procedures. During operation, the pressure vessel should be kept at stable pressure and temperature while in use. Rapid loading can cause the material at the existing minor defects in the container to fracture, reducing its toughness and increasing the likelihood of brittle failure. Frequent or large fluctuations in pressure are detrimental to the fatigue resistance of containers, and should be avoided as much as possible to maintain stable operating conditions. Sudden changes in temperature can generate large thermal stresses; therefore, it is also important to maintain a stable temperature. Pressure vessels must never be operated above their temperature limits. When the pressure exceeds the specified limit and the safety relief device fails to activate, emergency measures must be taken immediately to cut off the power supply. For water-cooled containers, if the water supply is interrupted and the temperature exceeds the specified limit, the operation must be stopped. For liquid storage, it must be filled according to the specified filling coefficient. Safety maintenance: Proper maintenance of pressure vessels is an important measure to extend their service life and prevent accidents. 1. Safety valves, pressure gauges, etc. are important measures to prevent pressure vessels from exceeding safe limits; it is necessary to strengthen their maintenance and conduct regular calibrations to ensure that these devices remain accurate and sensitive. 2. Prevent leakage from containers and pipelines. If the above phenomena occur, it indicates that the container is no longer in good condition and poses a risk; failure to address this issue promptly can lead to accidents. 3. The medium in some containers is corrosive; therefore, anti-corrosion measures should be taken, such as painting, spraying coatings, or installing linings. 4. Try to minimize vibrations of the pressure vessel to prevent fatigue cracks from occurring at the intake pipe. Oil residues, carbon deposits, and other contaminants accumulated in containers and pipelines should be removed promptly to prevent combustion and explosion accidents. In short, pressure vessels must adhere to a system of daily maintenance and upkeep, as well as regular inspection and repair. Safety must also be considered during maintenance and repair work. Before inspecting the container, in addition to using blind flanges to isolate connected pipelines, manholes and handholes must be opened. When working inside a container containing flammable or toxic substances, the container should be cleaned and purged, and ventilation should be enhanced. The container must be under the supervision of a dedicated person, and the voltage of hand-held electric tools used must not exceed 12V. After maintenance, pressure vessels must be thoroughly cleaned before being put back into operation, in order to prevent the presence of any substances remaining in the vessel or pipes that could react with the working medium – such as residual oil in oxygen vessels or water in chlorine vessels – thereby avoiding accidents.